Preparation of oligomers and co-oligomers of highly fluorinated sulfinic acids and salts thereof

ABSTRACT

There is provided a method for preparing oligomers and co-oligomers of highly fluorinated sulfuric acids and salts thereof.

FIELD

The present disclosure relates to highly fluorinated sulfinic acidoligomers and co-oligomers and salts thereof. The present disclosurerelates to methods of making highly fluorinated sulfinic acid oligomersand co-oligomers and salts thereof.

BACKGROUND

Fluorinated sulfinates have utility in fluoropolymer and hydrocarbonprocessing. Methods for the synthesis of fluorinated sulfinates andtheir use as intermediates have been widely reported in the literature.For example, perfluoroalkane sulfinates can be prepared from thecorresponding perfluoroalkanehalides via a dehalogenation andsulfination reaction, as reported in C. M. Hu, F. L. Quing, and W. Y.Huang, J Org Chem, 1991, 2801-2804 and W. Y. Huang, Journal of FluorineChemistry, 58, 1992, 1-8. Several reagent systems have been developedfor use in this reaction, such as sulfite plus an oxidant,hydroxymethane sulfinate, thiourea dioxide and sodium dithionite. Theuse of sodium dithionite as dehalogenating and sulfinating reagent hasalso been reported by W. Y. Huang, B. N. Huang and W. Wang in Acta Chim.Sinica (Engl. Ed.), 1986, 178-184, and Acta Chim. Sinica (Engl. Ed.),1986, 68-72. The later publication discloses that the reaction with anaqueous solution of the sodium dithionite is too slow for reactionsinvolving water-insoluble perfluoralkyl bromides, and that cosolventsare needed to improve the mutual solubility of the various reactants andpermit completion of the reaction within 30 to 35 hours. Mentionedcosolvents include acetonitrile, glycol and diethylene glycol.

In another example, F. H. Wu and B. N. Huang, Journal of Fluorine Chem,67, 1994, 233-234 reported that if DMF, acetonitrile or alcohols areused as cosolvent, both polyfluoroalkyl iodides and polyfluoroalkylbromides will react with sodium disulfite in neutral aqueous solution togive the corresponding sulfinates in good yield. In a similar manner,CF₃CCl₃ reacts with sodium disulfite to give the corresponding sodiumsulfinate. A disadvantage of preparing fluorinated sulfinates startingfrom the corresponding fluorinated iodide or bromide is that theresulting reaction product contains a large amount of by-products,particularly, inorganic salts which typically must be removed from thesulfinate.

Alternative processes for the preparation of fluorocarbon sulfinateshave also been disclosed, for example, in U.S. Pat. No. 3,420,877(Pavlik). This particular preparation involves reacting perfluoroalkylsulfonyl fluoride with an alkali metal sulfite or alkaline earth sulfitein an aqueous medium containing from about 10 to about 50 weight percentof a dissolved polar, inert organic solvent selected from the groupconsisting of dioxane, dimethoxyethane, di-n-butyl ether,tetrahydrofuran, and diethylene glycol diethyl ether. This processgenerally does not result in large amounts of salts that need to beremoved from the resultant product, but requires use of a cosolvent thatmay be toxic and may have a negative impact on processes in which thesulfinate is ultimately employed, e.g., free-radical polymerizationreactions. Reduction of these fluorinated sulfonyl fluorides usingNH₂NH₂ are also known to make the corresponding sulfinates. However, allknown processes are limited to making mono-sulfinates and di-sulfinates.

There continues to be a need for a process for preparing highlyfluorinated sulfinic acid oligomers and co-oligomers and salts thereofthat do not require the use of solvents and preferably do not requirefurther processing or purification of the resulting reaction mixture. Itis further desirable to have a favorable yield of the highly fluorinatedsulfinic acid oligomers and co-oligomers and salts thereof.

SUMMARY

In one aspect, there is provided a method for preparing an oligomercomprising:

(a) providing a highly fluorinated vinyl sulfonyl halide;

(b) oligomerizing the highly fluorinated vinyl sulfonyl halide with aninitiator to provide a highly fluorinated oligomeric sulfonyl halideaccording to the following formula (I):

(c) and, reducing the highly fluorinated oligomeric sulfonyl halide to ahighly fluorinated sulfinate oligomer according to the following formula(IV),

wherein X₁, X₂, and X₃ are independently selected from F, Cl and CF₃; Ris independently selected from H, I, Br, linear or branched alkyl, andlinear or branched fluoroalkyl group optionally containing caternaryheteroatoms; R1 is a linear or branched perfluorinated linking group,which may be saturated or unsaturated, substituted or unsubstituted, andoptionally comprises catenary heteroatoms; Y is a halide; M is a cation;and m is at least 2.

In another aspect, there is provided the method disclosed above wherestep (b) further comprises co-oligomerization of the highly fluorinatedsulfonyl halide according to formula (I) with a highly fluorinated vinylether to provide a structure according to formula (II):

wherein X₄, X₅, or X₆ are independently selected from H, F, Cl and CF₃;R2 is a linear or branched fluorinated linking group, which may besaturated or unsaturated and substituted or unsubstituted, andoptionally comprises catenary heteroatoms; G is selected from aperfluoroalkyl, a perfluoroalkoxy, a functional group, and combinationsthereof; n is at least 1; and wherein X₄, X₅, X₆, G and R2 are selectedsuch that the highly fluorinated vinyl ether according to formula (II)is different than the highly fluorinated oligomeric sulfonyl halideaccording to formula (I).

In still another aspect, there is provided the method disclosed abovewherein step (b) further comprises co-oligomerization of the highlyfluorinated sulfonyl halide according to formula (I) and/or highlyfluorinated vinyl ether according to formula (II) with anethylenically-unsaturated monomer to provide a structure according toformula (III):

wherein Z is derived from monomers selected from ethylene, propylene,tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene,vinylidene fluoride, vinyl fluoride, fluorinated alkyl vinyl ethers,fluorinated alkoxy vinyl ethers, fluorinated vinyl ethers containing afunctional group, perfluoro-1,3-dioxoles, and combinations thereof, andfurther wherein p is at least 1.

The above summary is not intended to describe each embodiment. Thedetails of one or more embodiments of the invention are also set forthin the description below. Other features, objects, and advantages willbe apparent from the description and from the claims.

DETAILED DESCRIPTION

As used herein, the term:

“a”, “an”, and “the” are used interchangeably and mean one or more; and“and/or” is used to indicate one or both stated cases may occur, forexample A and/or B includes, (A and B) and (A or B). Also herein,recitation of ranges by endpoints includes all numbers subsumed withinthat range (e.g., 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98, etc.).Also herein, recitation of “at least one” includes all numbers of oneand greater (e.g., at least 2, at least 4, at least 6, at least 8, atleast 10, at least 25, at least 50, at least 100, etc.).

“Oligomer” means less than 20,000 g/mol, less than 15,000 g/mol, lessthan 10,000 g/mol, less than 5,000 g/mol, less than 2,000 g/mol, lessthan 1,000 g/mol, and even less than 500 g/mol.

“Linking group” means a divalent linking group. In one embodiment, thelinking group includes at least 1 carbon atom (in some embodiments, atleast 2, 4, 8, 10, or even 20 carbon atoms). The linking group can be alinear or branched, cyclic or acyclic structure, that may be saturatedor unsaturated, substituted or unsubstituted, and optionally containsone or more hetero-atoms selected from the group consisting of sulfur,oxygen, and nitrogen, and/or optionally contains one or more functionalgroups selected from the group consisting of ester, amide, sulfonamide,carbonyl, carbonate, urethane, urea, and carbamate.

“Highly fluorinated” means repeating monomer units that areperfluorinated with perfluorinated or partially fluorinated end groupswhich may optionally contain chlorine on oligomers derived therefrom.For example, when a perfluorinated initiator is used, a perfluorinatedsulfinic acid oligomer is produced. In another example, when an organicinitiator is used, hydrogen atoms will be present in the “R” end groupsof formula (I) (shown above).

“Sulfinate” is used to indicate both sulfinic acids and sulfinic acidsalts. Also herein, “fluorosulfinate” and “fluorinated sulfinate” areused interchangeably to indicate sulfinic acids and sulfinic acid saltswhich contain at least one fluorine atom. Fluoroolefins are useful ascomonomers for making fluoropolymers.

Fluorosulfinates are useful for producing fluoropolymers without ionicends that benefit the processing of the polymers. A fluorosulfinicreactive monomer can be used as a surfactant, initiator and reactivemonomer giving unique branched fluoropolymers. Oligomers containingfluorosulfinic acid group can initiate chain growth to provide complexfluoropolymer structures, such as, for example, a comb fluoropolymerstructure.

The present disclosure relates to a method for preparing highlyfluorinated oligomeric sulfinic acids. In some embodiments, the methodfor preparing highly fluorinated oligomeric sulfinic acids includes thesteps of:

(a) providing a highly fluorinated vinyl sulfonyl halide;

(b) oligomerizing the highly fluorinated vinyl sulfonyl halide with aninitiator to provide a highly fluorinated oligomeric sulfonyl halideaccording to the following formula (I):

(c) and, reducing the highly fluorinated oligomeric sulfonyl halide to ahighly fluorinated sulfinate oligomer according to the following formula(IV),

In some embodiments, X₁, X₂, and X₃ are independently selected from F,Cl and CF₃. R is independently selected from hydrogen, iodine, bromine,linear or branched alkyl, and linear or branched fluoroalkyl groupoptionally containing caternary heteroatoms. In some embodiments, thealkyl group has up to 20 carbon atoms. In some embodiments, R1 is alinear or branched perfluorinated linking group. This linking group maybe saturated or unsaturated, substituted or unsubstituted, andoptionally comprises catenary heteroatoms.

In some embodiments, Y is a halide. Halides useful in the presentdisclosure include fluorine and chloride. M is a cation. Exemplarycations useful in the present disclosure include H⁺, NH₄ ⁺, PH₄ ⁺, H₃O⁺,Na⁺, Li⁺, Cs⁺, Ca⁺², K⁺, Mg⁺², Zn⁺², and Cu⁺², and/or an organic cationincluding, but not limited to N(CH₃)₄ ⁺, NH₂(CH₃)₂ ⁺, N(CH₂CH₃)₄ ⁺,NH(CH₂CH₃)₃ ⁺, NH(CH₃)₃ ⁺, ((CH₃CH₂CH₂CH₂)₄)P⁺, and the like, andcombinations thereof. For methods useful in the present disclosure, m isselected from any number of 2 or higher.

In some embodiments, the highly fluorinated vinyl sulfonyl halide is aperfluorovinyl sulfonyl halide, such as, for example, a perfluorovinylether sulfonyl fluoride. Exemplary perfluorovinyl ether sulfonylfluorides according to the present disclosure include, but are limitedto,

In some embodiments, the method for preparing highly fluorinatedoligomeric sulfinic acids also includes step (d) acidifying the highlyfluorinated sulfinate oligomer from step (c) and extracting a highlyfluorinated sulfinic acid oligomer therefrom. Any acid can be used instep (d). Exemplary acids include sulfuric acid, hydrochloric acid andother strong mineral acids, and the like, and combinations thereof.Extraction can be conducted using any known extraction techniques, suchas for example, using vacuum stripping and/or filtration with or withoutaddition of an additional component. Exemplary components include, butare not limited to, an alcohol, an ether, and the like. In someembodiments, methanol is a preferred. In some embodiments methyl-t-butylether is preferred.

In some embodiments, the method for preparing the highly fluorinatedoligomeric sulfinic acids also includes step (e) converting the highlyfluorinated sulfinic acid oligomer from step (d) to form a salt thereof.In some embodiments, step (e) is conducted using an organic base. Insome embodiments, step (e) is conducted using an inorganic base. In someembodiments, ammonium hydroxide is preferred. In some embodiments,potassium hydroxide is preferred.

In some embodiments, the method for preparing highly fluorinatedoligomeric sulfinic acids also includes sulfonate that is produced bypartial reduction of the highly fluorinated oligomeric sulfonyl halidefollowing hydrolysis of remaining sulfonyl halide to sulfonate.

In some embodiments, the method for preparing highly fluorinatedsulfinic acids also includes co-oligomerization of the highlyfluorinated oligomeric sulfonyl halide according to formula (I) with ahighly fluorinated vinyl ether to provide a structure according toformula (II):

In some embodiments, X₄, X₅, or X₆ are independently selected from H, F,Cl and CF₃. In some embodiments, R2 is a linear or branched fluorinatedlinking group. The linking group may be saturated or unsaturated andsubstituted or unsubstituted, and optionally comprises catenaryheteroatoms.

G is selected from a perfluoroalkyl, a perfluoroalkoxy, a functionalgroup, and combinations thereof. In some embodiments, the perfluoroalkylgroup has up to 30 carbon atoms. In some embodiments, theperfluoroalkoxy group has up to 30 carbon atoms. In some embodiments,when G is a functional group, the functional group is selected fromcarboxylic acids and derivatives thereof, nitriles, sulfonyl halides,sulphonates, imidates, amidines, alcohols, mercaptans, iodine, bromine,and the like, and combinations thereof.

The variable n is at least 1. For methods useful in the presentdisclosure, X₄, X₅, X₆, G and R2 are selected such that the highlyfluorinated vinyl ether according to formula (II) is different than thehighly fluorinated oligomeric sulfonyl halide according to formula (I).

In some embodiments, the highly fluorinated vinyl ether according toformula (II) is reduced, such as for example in step (c), to produce analcohol derivative of the highly fluorinated vinyl ether. For example,when the G in formula (II) is selected to be a carbonyl group, thehighly fluorinated vinyl ether according to formula (II) is reduced instep (c) to produce an alcohol derivative thereof.

R1 in formula (I) and R2 in formula (II) are linear or branchedfluorinated linking groups. In some embodiments, R1 and R2 areindependently selected from —(CF₂)_(a)—, —O(CF₂)_(a)—,—(CF₂)_(a)—O—(CF₂)_(b)—, —(CF₂)_(a)—[O—(CF₂)_(b)]_(c)—, and—[(CF₂)_(a)—O—]_(b)—[(CF₂)_(c)—O—]_(d),—(CF₂)_(a)—[O—(CF(CF₃)CF₂)_(b)]_(c), and combinations thereof, where a,b, c, and d are independently at least 1. Exemplary linear and branchedlinking groups that are useful as R1 and R2 in the present disclosureinclude, but are not limited to, —CF₂CF₂—, —CF₂CF₂CF₂CF₂—,—CF₂CF(CF₃)—O—CF₂CF₂—.

In some embodiments, the method for preparing highly fluorinatedsulfinic acids may also include, in step (b) shown above,co-oligomerization of the highly fluorinated vinyl sulfonyl halideaccording to formula (I) with an ethylenically-unsaturated monomer toprovide a structure according to formula (III):

In some embodiments, Z is derived from monomers selected from ethylene,propylene, tetrafluoroethylene, chlorotrifluoroethylene,hexafluoropropylene, vinylidene fluoride, vinyl fluoride, fluorinatedalkyl vinyl ethers, fluorinated alkoxy vinyl ethers, fluorinated vinylethers containing a functional group, perfluoro-1,3-dioxoles, and thelike, and combinations thereof. The variable p is at least 1.

In some embodiments, the ethylenically-unsaturated monomer according toformula (III) can be co-oligomerized with the highly fluorinated vinylsulfonyl halide according to formula (I) and the highly fluorinatedvinyl ether according to formula (II).

In some embodiments, when Z is an ethylenically-unsaturated monomercontaining a functional group, the functional group is selected frombromine and/or iodine. Exemplary ethylenically-unsaturated monomerscontaining a functional group are derived from one or more compounds ofthe following formula (V):

CX₂═CX(Z)

In some embodiments, each X is independently selected from hydrogen orfluorine. In some embodiments, Z is selected from iodine, bromine orR_(f)-U where U is selected from iodine or bromine, and R_(f) is aperfluorinated or partially perfluorinated alkylene group optionallycontaining oxygen atoms. In some embodiments, non-fluorinated bromo-oriodo-olefins, e.g., vinyl iodide and allyl iodide, can be used.Exemplary ethylenically-unsaturated monomer containing a functionalgroup include, but are not limited to:

CH₂═CHI CF₂═CHI CF₂═CFI CH₂═CHCH₂I CF₂═CFCF₂I CH₂═CHCF₂CF₂ICH₂═CHCF₂CF₂CH₂CH₂I CH₂═CH(CF₂)₄I CH₂═CH(CF₂)₄CH₂CH₂I CH₂═CH(CF₂)₆ICH₂═CH(CF₂)₆CH₂CH₂I CF₂═CFCH₂CH₂I CF₂═CFCF₂CF₂I CF₂═CFOCF₂CF₂ICF₂═CFOCF₂CF₂CH₂CH₂I CF₂═CFOCF₂CF₂CF₂I CF₂═CFOCF₂CF₂CF₂ CF₂ICF₂═CFOCF₂CF₂CF₂CH₂CH₂I CF₂═CFOCF₂CF₂CH₂I CF₂═CFOCF₂CF₂CF₂CH₂ICF₂═CFCF₂OCH₂CH₂I

CF₂═CFO(CF₂)₃OCF₂CF₂I

CH₂═CHBr CF₂═CHBr CF₂═CFBr CH₂═CHCH₂Br CF₂═CFCF₂Br CH₂═CHCF₂CF₂BrCF₂═CFOCF₂CF₂Br CF₂═CFC1 CF₂═CFCF₂Cl

and combinations thereof.

In some embodiments, the oligomerization step (b) is conducted in theabsence of a solvent. That is, a solvent is not added to the mixturebeing oligomerized or co-oligomerized in step (b). In some embodiments,the oligomerization step (b) is conducted in the presence of a solvent.Solvents useful in the present disclosure include perfluorocarbons,perfluoroethers, chlorofluoroethers, chlorocarbons, hydrofluoroethersand water, and the like, and combinations thereof.

The solvent should be present in an amount sufficient to allow adequatestirring and heat transfer during the reaction. In some embodiments, thesolvent can be removed after completion of the reaction.

Any conventional method may be used to remove the solvent, such asextraction, distillation under reduced pressure, column chromatography,and any other separation method.

In some embodiments, an initiator is used. Any conventional initiatorcan be used, such as, for example, persulfates, peroxides (e.g., organicperoxides, such as diacyl peroxides, peroxyesters, dialkyl peroxides,hyrdoperoxides, etc.), photo irradiation, gamma irradiation, azocompounds, and the like. In some embodiment, the preferred intiator isselected from peroxidic compounds. Hydrogen peroxide, acyl peroxidessuch as, for example, diacetyl peroxide, dipropionyl peroxide, dibutyrylperoxide, dibenzoyl peroxide, benzoyl acetyl peroxide, dilauroylperoxide, disuccinic peroxide or diglutaric peroxide may be mentionedhere, but only as examples. In addition, water-soluble peracids, such asperacetic acid, and their water-soluble salts (in particular theammonium, sodium or potassium salts) or their esters, such as, forexample, tert.-butyl peroxyacetate and tert.-butyl peroxypivalate, maybe mentioned. The water-soluble salts, in particular the ammonium,potassium and sodium salts of other peracids, such as peroxomono- andperoxodisulfates, perphosphates, perborates and percarbonates may alsobe employed. Perfluoroacyl peroxides or Ω-hydroperfluoroacyl peroxidesare furthermore suitable. Azo compounds useful in the present disclosureinclude azoisobutyronitrile and azo-2-cyanovaleric acid and the like. Insome embodiments, certain water-soluble azo compounds are preferred.Conventional active redox systems that generate radicals to an adequateextent at temperatures between 10° C. and 50° C. can also be employed asinitiators, above all in the low temperature range. An exemplary redoxsystems includes the combination of water-soluble peroxidic compounds,preferably peroxodisulfates, with hydrogen sulfite or with disulfite orits addition products with formaldehyde, with thiosulfate and withdiimine-liberating compounds, such as, for example, with hydrazine orazodicarboxamide may be mentioned, but only as example. The salts,preferably the alkali metal salts and, in particular, the ammoniumsalts, of the compounds mentioned are also present in the redoxcombinations. If the oligomerization takes place in an organic solvent,in each case those of the abovementioned catalysts must be selected suchthat they are adequately soluble in the solvent concerned.

In this process, the entire amount of initiator can be added at thebeginning of the oligomerization reaction in step (b). However, it maybe expedient in relatively large batches to add initiator continuouslyduring the course of the oligomerization in step (b). Equally, part ofthe amount of the initiator can alternatively be added at the beginningand the remainder in one or more batches can be added later. Theaddition of coactivators, i.e. for example, soluble salts of iron and ofsilver, may be advantageous, in particular when redox systems are usedas initiators.

Reducing agents useful in the present disclosure include those commonlyknown as reducing agents, such as, for example, those listed below.Exemplary reducing agents include metal hydrides, such as MeLH₄, whereMe is an alkaline metal and L is either an aluminum or a boron andMeH_(x), where Me is either an alkaline metal or an alkaline earthmetal, and x is 1 or 2. These types of reducing agents include, forexample, lithium aluminum hydride, lithium boron hydride, potassiumboron hydride, sodium boron hydride, sodium hydride, lithium hydride,potassium hydride, barium hydride, calcium hydride, and the like. Insome embodiments, the preferred reducing agent is sodium borohydride.

In some embodiments, useful reducing agents include reductive inorganicacids. These types of reducing agents include, for example, hydracidiodide, hydracid bromide, hydrophosphoric acid, hydracid sulfide,arsenious acid, phosphorous acid, sulfurous acid, nitrous acid, formicacid, oxalic acid, and the like. In some embodiments, useful reducingagents include mixtures of metals and acids. Metals useful in thesetypes of reducing agents include, for example, tin, iron, zinc, amalgamof zinc, and the like. Acids useful in these types of reducing agentsinclude, for example, hydrochloric acid, sulfuric acid, acetic acid,phosphoric acid, formic acid, trifluoromethane sulfonic acid,trifluoroacetic acid, trichloroacetic acid, and the like.

In some embodiments, useful reducing agents include organic metalcompounds, such as, for example, butyl lithium, Grignard reagent (suchas alkyl carbon atom of 1 to 8), aryl magnesium halide, triethylaluminum, trisobutyl aluminum, sodium-benzene, sodium-naphthalene, andthe like. In some embodiments, metal compounds with low valences areuseful reducing agents, such as, for example, stannous chloride, ferroussulfate, titanium trichloride, ferrous chloride, stannous sulfate,ferrous sulfide, stannous sulfide, ferrous bromide, stannous bromide,ferrous hydroxide, and the like. In some embodiments, reductive salts ofinorganic acids and compounds of the same are useful reducing agents.

These types of reducing agents include, for example, iodides, bromides,sulfides, phosphites, sulfites, arsenites, dithionites, nitrites,formates, and the like. Mixtures of metals, water, steam, alcohols oralkalis can also be used as reducing agents in the present disclosure.Also useful as reducing agents are reductive organic compounds, such as,for example, triethanolamine, acetaldehyde, formaldehyde, propylaldehyde, and the like, and reductive gases, such as, for example,carbon monooxide, sulfur dioxide, hydrogen iodide, hydrogen bromide,hydrogen sulfide, and the like. In some embodiments, a reducing agentuseful in the present disclosure is selected from at least one of sodiumborohydride, potassium borohydride, lithium aluminum hydride, NH₂NH₂,K₂SO₃, Na₂SO₃, NaHSO₃ and KHSO₃.

The following embodiments are representatives of the subject matter ofthe present application:

Embodiment 1

A method for preparing an oligomer comprising:

(a) providing a highly fluorinated vinyl sulfonyl halide;

(b) oligomerizing the highly fluorinated vinyl sulfonyl halide with aninitiator to provide a highly fluorinated oligomeric sulfonyl halideaccording to the following formula (I):

(c) and, reducing the highly fluorinated oligomeric sulfonyl halide to ahighly fluorinated sulfinate oligomer according to the following formula(IV),

wherein X₁, X₂, and X₃ are independently selected from F, Cl and CF₃; Ris independently selected from H, I, Br, linear or branched alkyl, andlinear or branched fluoroalkyl group optionally containing catenaryheteroatom; R1 is a linear or branched perfluorinated linking group,which may be saturated or unsaturated, substituted or unsubstituted, andoptionally comprises catenary heteroatoms; Y is a halide; M is a cation;and m is at least 2.

Embodiment 2

The method of embodiment 1 further comprising (d) acidifying the highlyfluorinated sulfinate oligomer from step (c) and extracting a highlyfluorinated sulfinic acid oligomer therefrom.

Embodiment 3

The method of embodiment 2 further comprising (e) converting the highlyfluorinated sulfinic acid oligomer from step (d) to form a salt thereof.

Embodiment 4

The method of embodiment 3 wherein the highly fluorinated sulfinic acidoligomer is converted to the salt thereof using an organic or inorganicbase.

Embodiment 5

The method of embodiment 3 wherein the highly fluorinated sulfinic acidoligomer is converted to the salt thereof using ammonium hydroxide.

Embodiment 6

The method of embodiment 3 wherein the highly fluorinated sulfinic acidoligomer is converted to the salt thereof using sodium or potassiumhydroxide.

Embodiment 7

The method of any of the preceding embodiments wherein step (b) furthercomprises co-oligomerization of the highly fluorinated sulfonyl halideaccording to formula (I) with a highly fluorinated vinyl ether toprovide a structure according to formula (II):

wherein X₄, X₅, or X₆ are independently selected from H, F, Cl and CF₃;R2 is a linear or branched fluorinated linking group, which may besaturated or unsaturated and substituted or unsubstituted, andoptionally comprises catenary heteroatoms; G is selected from aperfluoroalkyl, a perfluoroalkoxy, a functional group, and combinationsthereof; n is at least 1; and wherein X₄, X₅, X₆, G and R2 are selectedsuch that the highly fluorinated vinyl ether according to formula (II)is different than the highly fluorinated oligomeric sulfonyl halideaccording to formula (I).

Embodiment 8

The method according to embodiment 7 wherein when G is a functionalgroup, the functional group is selected from carboxylic acids andderivatives thereof, nitriles, sulfonyl halides, sulphonates, imidates,amidines, alcohols, mercaptans, iodine, bromine and combinationsthereof.

Embodiment 9

The method of embodiment 8 wherein when the functional group is acarbonyl group, the functional group is reduced to provide an alcoholderivative.

Embodiment 10

The method of embodiments 1, 2, 3, 4, 5, or 6 wherein step (b) furthercomprises co-oligomerization of the highly fluorinated oligomericsulfonyl halide with an ethylenically-unsaturated monomer to provide astructure according to formula (III):

wherein Z is derived from monomers selected from ethylene, propylene,tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene,vinylidene fluoride, vinyl fluoride, fluorinated alkyl vinyl ethers,fluorinated alkoxy vinyl ethers, fluorinated vinyl ethers containing afunctional group, perfluoro-1,3-dioxoles, and combinations thereof, andfurther wherein p is at least 1.

Embodiment 11

The method of embodiment 10 wherein the ethylenically-unsaturatedmonomer is selected from CH₂═CH₁, CF₂═CH₁, CF₂═CF₁, CH₂═CHCH₂I,CF₂═CFCF₂I, CH₂═CHCF₂CF₂I, CH₂═CHCF₂CF₂CH₂CH₂I, CH₂═CH(CF₂)₄I,CH₂═CH(CF₂)₄CH₂CH₂I, CH₂═CH(CF₂)₆I, CH₂═CH(CF₂)₆CH₂CH₂I, CF₂═CFCH₂CH₂I,CF₂═CFCF₂CF₂I, CF₂═CFOCF₂CF₂I, CF₂═CFOCF₂CF₂CH₂CH₂I, CF₂═CFOCF₂CF₂CF₂I,CF₂═CFOCF₂CF₂CF₂ CF₂I, CF₂═CFOCF₂CF₂CF₂CH₂CH₂I, CF₂═CFOCF₂CF₂CH₂I,CF₂═CFOCF₂CF₂CF₂CH₂I, CF₂═CFCF₂OCH₂CH₂I, CF₂═CFO(CF₂)₃OCF₂CF₂I,CH₂═CHBr, CF₂═CHBr, CF₂═CFBr, CH₂═CHCH₂Br, CF₂═CFCF₂Br, CH₂═CHCF₂CF₂Br,CF₂═CFOCF₂CF₂Br, CF₂═CFCl, CF₂═CFCF₂Cl, and combinations thereof.

Embodiment 12

The method of embodiment 7, 8, or 9 wherein step (b) further comprisesco-oligomerization of the highly fluorinated sulfonyl halide with anethylenically-unsaturated monomer to provide a structure according toformula (III):

wherein Z is derived from monomers selected from ethylene, propylene,tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene,vinylidene fluoride, vinyl fluoride, fluorinated alkyl vinyl ethers,fluorinated alkoxy vinyl ethers, fluorinated vinyl ethers containing afunctional group, perfluoro-1,3-dioxoles, and combinations thereof, andfurther wherein p is at least 1.

Embodiment 13

The method according to any of the preceding embodiments wherein R1 andR2 are independently selected from: —(CF₂)_(a)—, —O(CF₂)_(a)—,—(CF₂)_(a)—O—(CF₂)_(b)—, —(CF₂)_(a)—[O—(CF₂)_(b)]_(c)—,—(CF₂)_(a)—[O—(CF(CF₃)CF₂)_(b)]_(c)—, and—[(CF₂)_(a)—O—]_(b)—[(CF₂)_(c)—O—]_(d)—, and combinations thereof,wherein a, b, c, and d are independently at least 1.

Embodiment 14

The method according to any of the preceding embodiments, wherein R1 andR2 are independently selected from: —CF₂CF₂—, —CF₂CF₂OCF₂CF₂—,—CF₂CF(CF₃)—O—CF₂CF₂—.

Embodiment 15

The method of any of the preceding embodiments further comprising aninitiator in step (a).

Embodiment 16

The method of embodiment 15 wherein the initiator is selected from apersulfate, a peroxide, photo irradiation, gamma irradiation, and an azocompound.

Embodiment 17

The method of embodiment 15 wherein the initiator is a perfluorinatedperoxide.

Embodiment 18

The method of embodiment 17 wherein the perfluorinated peroxide isselected from CF₃OC₂F₄COOOCOC₂F₄OCF₃ and C₃F₇COOOCOC₃F₇.

Embodiment 19

The method of any of the preceding embodiments wherein theoligomerization in step (b) is conducted in the absence of a solvent.

Embodiment 20

The method of any of the preceding embodiments wherein theoligomerization in step (b) is conducted in the presence of a solvent.

Embodiment 21

The method of any of the preceding embodiments wherein theoligomerization in step (b) is conducted as aqueous emulsionoligomerization.

Embodiment 22

The method of any of the preceding embodiments wherein theoligomerization in step (b) is conducted under an inert atmosphere.

Embodiment 23

The method of any of the preceding embodiments wherein the highlyfluorinated oligomeric sulfonyl halide is a perfluorovinyl sulfonylhalide.

Embodiment 24

The method of any of embodiment 23 wherein the perfluorovinyl sulfonylhalide is a perfluorovinyl ether sulfonyl fluoride.

Embodiment 25

The method of embodiment 24 where in the perfluorovinyl ether sulfonylfluoride is selected from:

and combinations thereof.

Embodiment 26

The method according to any of the preceding embodiments wherein thereduction step (c) is conducted using a reducing agent.

Embodiment 27

The method according to any of the preceding embodiments where in thereduction step (c) is conducted using sodium borohydride, potassiumborohydride, lithium aluminum hydride, NH₂NH₂, K₂SO₃, Na₂SO₃, NaHSO₃ andKHSO₃ as the reducing agent.

EXAMPLES

The following examples are merely for illustrative purposes and are notmeant to limit in any way the scope of the appended claims. All parts,percentages, ratios, and the like in the examples are by weight, unlessnoted otherwise. All materials used herein were obtained fromSigma-Aldrich Chemical Company; Milwaukee, Wis. unless otherwise noted.

Materials

Material Source MV4S CF₂═CF—O—C₄F₈—SO₂F, made as described in theExample (section A to C) of U.S. Pat. No. 6,624,328 (Guerra) LUPEROX 575t-amyl-2-ethyl hexanoate peroxide, commercially available from Arkema,Philadelphia, PA LUPEROX TAEC t-amyl peroxy 2-ethylhexyl carbonate,commercially available from Arkema, Philadelphia, PA VAZO 67EtMeC(CN)—N═N—CEtMeCN commercially available from DuPont, Wilmington,Delaware CTFE-Dimer ClCFClCF₂CFClCF₂Cl and commercially available fromHalocarbon Products Corp., River Edge, NJ VDF Vinylidene fluoride,commercially available from Sigma- Aldrich Chemical Company; Milwaukee,Wisconsin MV5CO2CH3 CF₂═CF—O—C₅F₁₀—CO₂CH₃ made as per Example 9 belowMV31 CF₂═CF—O—C₃F₆—O—CF₃ made as per Example 8 of U.S. Pat. No.6,255,536 (Worm et al.) MV3b2S CF₂═CF—O—CF₂CF(CF₃)—OC₂F₄—SO₂F,Perfluoro(4-methyl-3,6- dioxaoct-7-ene)sulfonyl fluoride available fromSynQuest Lab, Alachua FL. o-MV4S R—[CF₂CF(OC₄F₈SO₂F)]n-R where n = 2-25and R can be C₄F₉, CF₃OCF₂CF₂, I, H, COOH, C₂H₅ and/or C₇H₁₅ o-MV4SO2HR—[CF₂CF(OC₄F₈SO₂H)]n-R where n = 2-5 and R can be C₄F₉, I, H, C₂H₅and/or C₇H₁₅ o-MV4SO2NH4 R—[CF₂CF(OC₄F₈SO₂NH₄)]n-R where n = 2-5 and Rcan be C₄F₉, I, H, C₂H₅ and/or C₇H₁₅ o-MV3b2SR—[CF₂CF(OCF₂CF(CF₃)OC₂F₄SO₂F)]n-R where n = 2-5 and R can be H, C₂H₅and/or C₇H₁₅ o-MV3b2SO2H R—[CF₂CF(OCF₂CF(CF₃)OC₂F₄SO₂H)]n-R where n =2-5 and R can be H, C₂H₅ and/or C₇H₁₅ o-MV3b2SO2NH4R—[CF₂CF(OCF₂CF(CF₃)OC₂F₄SO₂NH₄)]n-R where n = 2-5 and R can be H, C₂H₅and/or C₇H₁₅

Example 1

200 grams (0.53 mol) of MV4S and 20 grams (0.09 mol) of “LUPEROX 575”were charged to an evacuated 600 ml reactor, such as the reactorcommercially available under the trade designation “600 ml SERIES 4520PARR” from Parr Instruments, Moline, Ill. (“600 ml PARR reactor”). Themixture was stirred and heated to 65° C. for 20 hours. A slight pressurerise was measured and vented after the reaction reached 20° C. A productmixture of 217 grams was drained and fractionated to give 97 grams ofunreacted MV4S and 106 grams of oligomerized MV4S (o-MV4S) for a 53%yield. A 38 gram sample of the o-MV4S was heated under vacuum to removea cut boiling at 145° C. and 4.6 mm. The higher boiling product of 28.4grams remained in the pot. The 28.4 grams of higher boiling material wassubjected to Liquid Chromatography-Mass Spectroscopy (LCMS) and relativeareas indicated the general structure R—[CF₂CF(OC₄F₈SO₂F)]_(n)—R where nequaled 2 to 5 and R was H, C₂H₅ and/or C₇H₁₅. The average oligomer had2.9 units and an average molecular weight of 1200 grams per mole.

Example 2

6.3 grams (0.17 mol) of sodium borohydride in 100 grams oftetrahydrorfuran (THF) was charged to a 500 ml 3-neck round bottom flaskand stirred. 25 grams (0.06 mol) of o-MV4S made in Example 1 (having anaverage of 2.9 oligomer units) was dissolved in 50 grams of THF andadded over 15 minutes. A slight exothermic reaction occurred uponaddition of the o-MV4S solution. The mixture was allowed to react at 65°C. for two hours. Solvent was vacuum stripped and 14 grams ofconcentrated sulfuric acid in 200 grams of water was added at 20° C.This mixture was vacuum stripped and the resulting solids were extractedwith 100 grams of methanol. The extracted mixture was then filtered andvacuum stripped again to give 26.5 grams of tacky solid product that wasthen diluted to 50 grams with water. Nuclear magnetic resonancespectroscopy (NMR) gave the desired o-MV4SO2H for a 98% yield.

Example 3

200 grams (0.53 mol) of MV4S, 27 grams (0.12 mol) of “LUPEROX 575” and52 grams of CTFE-Dimer were placed in an evacuated 600 ml PARR reactorand the mixture was stirred and heated to 65° C. for 20 hours. A slightpressure rise was measured and vented after the reaction was at 20° C. Aproduct mixture of 268 grams was drained and fractionated to give 50grams of o-MV4S having a boiling point greater than 225° C. at 15 mmvacuum. Relative area percents from LCMS showed oligomers with thegeneral structure of R—[CF₂CF(OC₄F₈SO₂F)]n-R where n equaled 2 to 5 andR was one of H, C₂H₅ and/or C₇H₁₅. The average oligomer had 3.2 unitsand an average molecular weight of 1320 grams per mole under thisreaction condition and work up.

Example 4

In a 1 liter 3-neck round bottom flask were added 40 grams (0.11 mol) ofo-MV4S product from Example 3 in 100 grams of THF to a stirred solutionof 9 grams (0.24 mol) of sodium borohydride in 100 grams of THF. Aslight exothermic reaction occurred within 10 minutes of adding theo-MV4S solution. The reaction was allowed to run at 65° C. for 20 hours.25 grams of concentrated sulfuric acid in 200 grams of water was addedat 20° C. A top product phase of 135 grams of product with THF wasvacuum stripped. A 50 gram methanol charge was used to dissolve theproduct and this was filtered and vacuum stripped to give 35 grams ofo-MV4SO2H. NMR showed the presence of the desired o-MV4SO2H.

Example 5

The ammonium salt was made by adding 35 grams of o-MV4SO2H made inExample 4 to 6.1 grams (0.1 mol) of ammonia as 27% ammonium hydroxideand vacuum stripping to give 38 grams of o-MV4SO2NH4 salt as a tackysolid. No melting point was found and at 209° C. onset of decompositionwas measured for o-MV4SO2NH4.

Example 6

In a 100 ml bottle was charged 26 grams (0.07 mol) of MV4S, 50 grams ofdistilled water, 1 gram (0.0004 mol) of 50% solution of o-MV4SO2NH4 madein Example 5, 0.3 grams (0.001 mol) of sodium persulfate and 0.6 grams(0.003 mol) of potassium phosphate. The solution was nitrogen purged andplaced in a launder-ometer, such as the device commercially availableunder the trade designation “Launder-Ometer M228AA” from SDL Atlas, RockHill, South Caroline, for 20 hours at 80° C. 15 grams of unreacted MV4Swas recovered as a lower phase. The remaining solution was freeze thawedto precipitate 5 grams of viscous cold flowing polymer that wassubjected to LCMS and found to have a molecular weight that was too highfor detection by this method. ¹⁹F NMR showed presence of the desiredo-MV4S having the general structure R—[CF₂CF(OC₄F₈SO₂F]n-R where nequaled an average number of 25 and R was COOH and H. The averageoligomer had an average molecular weight of 9,600 grams per mole underthis reaction condition and work up.

Example 7

100 grams (0.26 mol) of MV4S, 17 grams (0.07 mol) of “LUPEROX 575” and103 grams of CTFE-Dimer were charged to an evacuated 600 ml PARRreactor. The mixture was stirred and 17 grams (0.27 mol) of vinylidenefluoride was charged. The resulting mixture was heated to 65° C. for 20hours. A slight pressure rise was measured and vented after the reactionwas at 20° C. A product mixture of 207 grams was drained andfractionated to give 57 grams of co-oligomeric o-MV4S/VDF having a 50%yield based on input monomers with a boiling point greater than 75° C.at 15 mm vacuum. Relative area percents from LCMS showed co-oligomerswith the general structure of R—[CF₂CF(OC₄F₈SO₂F)]x-[CH₂CF₂]y-R where xand y equaled 2 to 5 and R was one of H, C₂H₅ and/or C₇H₁₅. The averageco-oligomer had 3.1 units and an average molecular weight of 1478 gramsper mole under this reaction condition and work up.

Example 8

100 grams (0.26 mol) of MV4S, 15 grams (0.04 mol) of C₄F₉I, 10 grams(0.04 mol) of “LUPEROX 575” and 25 grams of CTFE-Dimer were charged toan evacuated 600 ml PARR reactor. The mixture was stirred and heated to65° C. for 20 hours. A slight pressure rise was measured and ventedafter the reaction reached 20° C. A product mixture of 145 grams wasdrained and fractionated to give 9 grams of oligomeric o-MV4S with aboiling point greater than 180° C. at 15 mm vacuum. Relative areapercents from LCMS showed oligomers with the general structure ofR—[CF₂CF(OC₄F₈SO₂F)]n-R where n equaled 2 to 5 and R was one of C₄F₉, I,H, C₂H₅ and/or C₇H₁₅. The average oligomer had 3.2 units and an averagemolecular weight of 1350 grams per mole under this reaction conditionand work up.

Example 9

6.1 grams of KF (0.1 mol), 390 grams of diglyme were charged in a 600 mlPARR reactor and cooled to −5° C. with stirring. 170 grams ofperfluoroadipoyl fluoride (0.87 mol) (available from Exfluor Research inAustin, Tex.) was charged to the reactor followed by 140 grams (0.85mol) of hexafluoropropylene oxide (available from E. I. du Pont deNemours and Company, Wilmington, Del.) and the reaction proceeded forover one hour. The reaction was heated to 25° C. and 250 grams ofproduct FCOC₅F₁₀—O—CF(CF₃)COF distilled over at 135° C. A 2-liter 3-neckround bottom flask was charged with 192 grams (1.8 mol) of Na₂CO₃, 390grams of diglyme and stirred. 250 grams (0.69 mol) ofFCOC₅F₁₀—O—CF(CF₃)COF was slowly added and the reaction temperatureheated up to 71° C. The slurry was heated up to 162° C. to decarboxylatethe slurry until no more CO₂ was evolved. The reaction was cooled to 25°C. and 215 grams (2.19 mol) of concentrated H₂SO₄ in 350 grams of waterwas added. A top phase of 540 grams was further washed with 64 grams ofconcentrated H₂SO₄ in 200 grams of water to obtain 317 grams of a bottomphase as a crude product. The bottom phase product was esterified with116 grams (3.63 mol) of methanol and 92 grams (0.94 mol) of concentratedH₂SO₄ by heating to 82° C. for 20 hours. The reaction was cooled to 25°C. and 200 grams of water was added to isolate 189 grams of the bottomphase product as the crude product. Vacuum distillation yielded 129grams (0.32 mol) of CF₂═CF—O—C₅F₁₀—CO₂—CH₃ with a boiling point of 132°C./15 mm.

100 grams (0.26 mol) of MV4S, 20 grams (0.05 mol) of MV5CO₂CH₃, 10 grams(0.04 mol) of “LUPEROX 575” and 25 grams of CTFE-Dimer were charged toan evacuated 600 ml PARR reactor. The mixture was stirred and heated to65° C. for 20 hours. A slight pressure rise was measured and ventedafter the reaction was at 20° C. A product mixture of 144 grams wasdrained and fractionated to give 24 grams of co-oligomerico-MV4S/MV5CO₂CH₃ with a boiling point greater than 225° C. at 15 mmvacuum. Relative area percents from LCMS showed oligomers with thegeneral structure of R—[CF₂CF(OC₄F₈SO₂F)]x-[CF₂CF(OC₅F₁₀CO₂CH₃)]y-Rwhere x and y equaled 2 to 5 and R was one of H, C₂H₅ and/or C₇H₁₅. Theaverage co-oligomer had 3.2 units and an average molecular weight of1320 grams per mole under this reaction condition and work up.

Example 10

To a 250 milliliter 3-neck round bottom flask were added 18 grams (0.02mol) of o-MV4S/MV5CO2CH3 product from Example 9 in 20 grams of THF to astirred solution of 1.5 grams (0.04 mol) of sodium borohydride in 50grams of THF. A slight exothermic reaction occurred with the additionwithin 10 minutes of adding the o-MV4S/MV5CO2CH3 solution. The reactionwas allowed to run at 65° C. for 1 hour. 10 grams of concentratedsulfuric acid in 50 grams of water was added at 20° C. A 50 grammethyl-t-butyl ether charge was used to extract the product and vacuumstripped to give 17 grams ofR—[CF₂CF(OC₄F₈SO₂H)]x-[CF₂CF(OC₅F₁₀CH₂OH)]y-R where x and y equaled 2 to5 and R was one of H, C₂H₅ and/or C₇H₁₅. Nuclear magnetic resonancespectroscopy (NMR) showed the desired co-oligomer having bothfluorosulfinic acid and fluoroalcohol groups with a 94% yield.

Example 11

100 grams (0.26 mol) of MV4S, 14 grams (0.04 mol) of MV31, 10 grams(0.04 mol) of “LUPEROX 575” and 25 grams of CTFE-Dimer were charged toan evacuated 600 ml PARR reactor. The mixture was stirred and heated to65° C. for 20 hours. A slight pressure rise was measured and ventedafter the reaction was at 20° C. A product mixture of 146 grams wasdrained and fractionated to give 23 grams of co-oligomeric o-MV4S/MV31with a boiling point greater than 225° C. at 15 mm vacuum. Relative areapercents from LCMS showed oligomers with the general structure ofR—[CF₂CF(OC₄F₈SO₂F)]x-[CF₂CF(OC₃F₆OCF₃]y-R where x and y equaled 2 to 5and R was one of H, C₂H₅ and/or C₇H₁₅. The average co-oligomer had 3.4units and an average molecular weight of 1375 grams per mole under thisreaction condition and work up.

Example 12

An evacuated 600 ml PARR reactor was charged with 50 grams (0.11 mol) ofMV3b2S, 7 grams (0.03 mol) of “LUPEROX 575” and 196 grams of CTFE-Dimer.The mixture was stirred and heated to 65° C. for 20 hours. A slightpressure rise was measured and vented after the reaction was at 20° C. Aproduct mixture of 248 grams was drained and fractionated to give 8grams of o-MV3b2S having a boiling point greater than 225° C. at 15 mmvacuum. Relative area percents from LCMS showed oligomers with thegeneral structure of R—[CF₂CF(OCF₂CF(CF₃)OC₂F₄SO₂F)]n-R where n equaled2 to 5 and R was one of H, C₂H₅ and/or C₇H₁₅. The average oligomer had2.5 units and an average molecular weight of 1250 grams per mole underthis reaction condition and work up.

Example 13

To a 250 milliliter 3-neck round bottom flask was added 6 grams (0.01mol) of o-MV3b2S product from example 12 in 20 grams of THF to a stirredsolution of 1.5 grams (0.03 mol) of sodium borohydride in 50 grams ofTHF. A slight exothermic reaction occurred with the addition within 10minutes of adding the o-MV3b2S solution. The reaction was allowed to runat 65° C. for 1 hour. 10 grams of concentrated sulfuric acid in 50 gramsof water was added at 20° C. A 50 gram methyl-t-butyl ether charge wasused to extract the product, which was then and vacuum stripped to give5.3 grams of o-MV3b2SO2H (91% yield). Nuclear magnetic resonancespectroscopy (NMR) confirmed the presence of the desired o-MV3b2SO2H.

Example 14

The ammonium salt was made by adding 5 grams of the o-MV3b2SO2H made inexample 13 to 6.1 grams (0.1 mol) of ammonia as 27% ammonium hydroxideand vacuum stripping to give 5.2 grams of o-MV3b2SO2NH4 salt as a tackysolid. The melting point was 156° C. and onset of decomposition was 183°C.

Example 15

280 g (1.2 mol) CF₃OC₂F₄COF (made by electrochemical fluorination asdescribed in example 2 of U.S. Pat. No. 2,713,593 to Brice et al) wasadded to excess methanol cooled to −20° C. in a 1 L 3-neck round bottomflask. This was then water washed to isolate 295 g (1.2 mol)CF₃OC₂F₄CO₂CH₃ as the fluorochemical lower phase. A charge of 89 g (1.35mol) KOH in 150 g water was then added to the previous fluorochemical tomake the CF₃OC₂F₄CO₂K salt. This was dried and acidified with 150 g ofconcentrated H₂SO₄ in 150 g water and vacuumed distilled to isolate 314g (1.3 mol) of CF₃OC₂F₄CO₂H. 50 g (0.22 mol) CF₃OC₂F₄CO₂H, 4 gdimethylformamide and 30 g (0.2.5 mol) thionyl chloride were reacted ina 500 mL 3-neck round bottom flask at 72° C. for one hr followed bydistillation to give 46 g (0.19 mol) CF₃OC₂F₄COCl. To a 250 ml 3-neckround bottom flask was added 4.7 g (0.05 mol) 35% HOOH which was thencooled to 0° C. with stirring followed by the addition of 4 g (0.1 mol)of NaOH in 90 g water. The reaction was kept at 10° C. and held for 30min followed by addition at 10° C. of 20 g (0.08 mol) CF₃OC₂F₄COCl in180 g of “FC-72 FLUORINERT” (commercially available from 3M Company, St.Paul, Minn.). The solution was stirred at 10° C. for 30 min and thelower phase was removed containing 10 weight % CF₃OC₂F₄COOOCOC₂F₄OCF₃ in“FC-72 FLUORINERT” confirmed by FNMR and FTIR. 120 g (0.32 mol) MV4S wasadded to a 500 ml 3-neck round bottom flask with a stir bar and cooledto 0° C. This was followed by addition of 100 g of 10 weight percent(0.02 mol) CF₃OC₂F₄COOOCOC₂F₄OCF₃ in “FC-72 FLUORINERT” with stirring at10° C. for 2 hrs. The solution was further reacted for 20 hrs at 25° C.The product mixture was fractionated to give 11 g of o-MV4S having aboiling point greater that 150° C. at 8 mm vacuum. ¹⁹F NMR confirmed thedesired perfluoro o-MV4S having CF₃OCF₂CF₂ end groups and the generalstructure CF₃OCF₂CF₂—[CF₂CF(OC₄F₈SO₂F)]n-CF₂CF₂OCF₃ where n was anaverage of 15. The oligomer had an average molecular weight of 6050 gper mole under this reaction condition and work up.

Example 16

50 grams of MV4S was oligomerized with 6.21 grams of “LUPEROX TAEC” at120° C. under nitrogen for 24 hours. The low boiling fractions werestripped out at 120° C. under vacuum to yield 31 grams of a viscousliquid with a 62% isolated yield. FTIR showed a signal at 2968 cm⁻¹ forCH from the hydrocarbon initiator and strong signals at 1463, 1349,1212, 1148 and 1072 cm⁻¹ for C—F and —SO₂F groups. ¹⁹F NMR showed nosignal for a CF═CFO— group, two signals for —CF₂O— at −81 and −87 ppm, aSO₂F signal at +43 ppm, —CF₂SO₂F signal at −110 ppm, and CF₂CF₂— signalsat −123 and −128. The oligomerized vinyl signals of —(CF₂CF(O—)- wereseen at −121 and −147 ppm with complicated multiplets. From LCMSanalysis the oligomer had an average of 3.2 units and an averagemolecular weight of 1320 grams per mole.

25.6 grams of the above viscous oligomer liquid (˜0.067 eq —SO₂F) in 37grams of THF solvent was treated with 0.5 grams of NaBH₄ (0.0132 mol) at−5 to 10° C. under nitrogen for 20 minutes followed by reaction at 20°C. for 2 additional hours. ¹⁹F NMR indicated 20% —SO₂F (+43 ppm) wasreacted to give the corresponding —SO₂M, the corresponding signal of—CF₂SO₂F at −111 ppm was decreased and a new signal at −132 ppm for—CF₂SO₂M appeared. 0.28 grams of NaBH₄ (total 0.78 grams, 0.0206 mole)was added at −5 to 10° C. over 20 minutes followed by reaction at 20° C.for 2 hours. The conversion was increased to 36%. Repeating the additionof NaBH₄ a third time the conversion was increased to 50% when 1.1 gramsof total NaBH₄ (0.029 mol) was added. ¹⁹F NMR indicated—OCF₂CF₂CF₂CF₂SO₂M with chemical shifts at −126, −128 and −132, and—OCF₂CF₂CF₂CF₂SO₂F with chemical shifts at −123, −128 and −111 ppm. Theremaining signal of —SO₂F was seen at +42 ppm.

5 grams water was added with stirring to the above partially reducedoligomer solution in THF to destroy any unreacted reducing agent. Thissolution was then treated with 10% KOH aqueous solution at 20° C. whilestirring until the pH of solution was basic (pH greater than 9). Thesolution was stirred at 20° C. for another 30 minutes. ¹⁹F NMR indicatedthe —SO₂F signal at +42 ppm had completely disappeared. Afteracidification of the solution with 2NH₂SO₄ to a pH of less than 2 themixture was extracted with methyl-t-butyl ether (3×50 mL). Afterstripping out the solvent, 32 grams of a wet product was obtained. Thewet product was dissolved in 20 grams of water. ¹⁹F NMR analysis of thesolution indicated about 50 wt % solids and a mole ratio of —CF₂SO₂H(−132 ppm) and —CF₂SO₃H (−111 ppm) of 54:46.

Example 17

Similar to what was done in Example 16, 50 grams of MV4S wasoligomerized with 2.81 grams of VAZO 67 (5.6 wt %) under nitrogen at120° C. for 24 hours. Filtration to remove solids at 25° C., thefiltered solution was stripped at 100° C. under full vacuum to removelow boiling point components. 9.7 grams of high viscous liquid oligomerswere obtained (19% yield). ¹⁹F NMR analysis showed no more CF═CFO—signal. From LCMS analysis the oligomer had an average of 2.6 units andan average molecular weight of 1071 grams per mole.

The complete disclosures of the patents, patent documents, andpublications cited herein are incorporated by reference in theirentirety as if each were individually incorporated. Variousmodifications and alterations to this invention will become apparent tothose skilled in the art without departing from the scope and spirit ofthis invention. It should be understood that this invention is notintended to be unduly limited by the illustrative embodiments andexamples set forth herein and that such examples and embodiments arepresented by way of example only with the scope of the inventionintended to be limited only by the claims set forth herein as followsand multi-layer articles created by this process.

1. A method for preparing an oligomer comprising: (a) providing a highlyfluorinated vinyl sulfonyl halide; (b) oligomerizing the highlyfluorinated vinyl sulfonyl halide with an initiator to provide a highlyfluorinated oligomeric sulfonyl halide according to the followingformula (I):

(c) and, reducing the highly fluorinated oligomeric sulfonyl halide to ahighly fluorinated sulfinate oligomer according to the following formula(IV),

wherein X₁, X₂, and X₃ are independently selected from F, Cl and CF₃; Ris independently selected from H, I, Br, linear or branched alkyl, andlinear or branched fluoroalkyl group optionally a heteroatom; R1 is alinear or branched perfluorinated linking group, which may be saturatedor unsaturated, substituted or unsubstituted, and optionally comprises aheteroatom; Y is a halide; M is a cation; and m is at least
 2. 2. Themethod of claim 1 further comprising (d) acidifying the highlyfluorinated sulfinate oligomer from step (c) and extracting a highlyfluorinated sulfinic acid oligomer therefrom.
 3. The method of claim 2further comprising (e) converting the highly fluorinated sulfinic acidoligomer from step (d) to form a salt thereof.
 4. The method of claim 3wherein the highly fluorinated sulfinic acid oligomer is converted tothe salt thereof using an organic or inorganic base.
 5. The method ofclaim 3 wherein the highly fluorinated sulfinic acid oligomer isconverted to the salt thereof using ammonium hydroxide.
 6. The method ofclaim 3 wherein the highly fluorinated sulfinic acid oligomer isconverted to the salt thereof using sodium or potassium hydroxide. 7.The method of claim 1 wherein step (b) further comprisesco-oligomerization of the highly fluorinated sulfonyl halide accordingto formula (I) with a highly fluorinated vinyl ether to provide astructure according to formula (II):

wherein X₄, X₅, or X₆ are independently selected from H, F, Cl and CF₃;R2 is a linear or branched fluorinated linking group, which may besaturated or unsaturated and substituted or unsubstituted, andoptionally comprises catenary heteroatoms; G is selected from aperfluoroalkyl, a perfluoroalkoxy, a functional group, and combinationsthereof; n is at least 1; and wherein X₄, X₅, X₆, G and R2 are selectedsuch that the highly fluorinated vinyl ether according to formula (II)is different than the highly fluorinated oligomeric sulfonyl halideaccording to formula (I).
 8. The method of claim 7 wherein when G is afunctional group, the functional group is selected from carboxylic acidsand derivatives thereof, nitriles, sulfonyl halides, sulphonates,imidates, amidines, alcohols, mercaptans, iodine, bromine andcombinations thereof.
 9. The method of claim 1 wherein step (b) furthercomprises co-oligomerization of the highly fluorinated oligomericsulfonyl halide with an ethylenically-unsaturated monomer to provide astructure according to formula (III):

wherein Z is derived from monomers selected from ethylene, propylene,tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene,vinylidene fluoride, vinyl fluoride, fluorinated alkyl vinyl ethers,fluorinated alkoxy vinyl ethers, fluorinated vinyl ethers containing afunctional group, perfluoro-1,3-dioxoles, and combinations thereof, andfurther wherein p is at least
 1. 10. The method of claim 9 wherein theethylenically-unsaturated monomer is selected from CH₂═CH₁, CF₂═CH₁,CF₂═CF₁, CH₂═CHCH₂I, CF₂═CFCF₂I, CH₂═CHCF₂CF₂I, CH₂═CHCF₂CF₂CH₂CH₂I,CH₂═CH(CF₂)₄I, CH₂═CH(CF₂)₄CH₂CH₂I, CH₂═CH(CF₂)₆I, CH₂═CH(CF₂)₆CH₂CH₂I,CF₂═CFCH₂CH₂I, CF₂═CFCF₂CF₂I, CF₂═CFOCF₂CF₂I, CF₂═CFOCF₂CF₂CH₂CH₂I,CF₂═CFOCF₂CF₂CF₂I, CF₂═CFOCF₂CF₂CF₂ CF₂I, CF₂═CFOCF₂CF₂CF₂CH₂CH₂I,CF₂═CFOCF₂CF₂CH₂I, CF₂═CFOCF₂CF₂CF₂CH₂I, CF₂═CFCF₂OCH₂CH₂I,CF₂═CFO(CF₂)₃OCF₂CF₂I, CH₂═CHBr, CF₂═CHBr, CF₂═CFBr, CH₂═CHCH₂Br,CF₂═CFCF₂Br, CH₂═CHCF₂CF₂Br, CF₂═CFOCF₂CF₂Br, CF₂═CFCl, CF₂═CFCF₂Cl, andcombinations thereof.
 11. The method of claim 7 wherein step (b) furthercomprises co-oligomerization of the highly fluorinated sulfonyl halidewith an ethylenically-unsaturated monomer to provide a structureaccording to formula (III):

wherein Z is derived from monomers selected from ethylene, propylene,tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene,vinylidene fluoride, vinyl fluoride, fluorinated alkyl vinyl ethers,fluorinated alkoxy vinyl ethers, fluorinated vinyl ethers containing afunctional group, perfluoro-1,3-dioxoles, and combinations thereof, andfurther wherein p is at least
 1. 12. The method of claim 1 wherein R1and R2 are independently selected from: —(CF₂)_(a)—, —O(CF₂)_(a)—,—(CF₂)_(a)—O—(CF₂)_(b)—, —(CF₂)_(a)—[O—(CF₂)_(b)]_(c)—,—(CF₂)_(a)—[O—(CF(CF₃)CF₂)_(b)]_(c)—, and—[(CF₂)_(a)—O]_(b)—[(CF₂)_(c)—O—]_(d)—, and combinations thereof,wherein a, b, c, and d are independently at least
 1. 13. The method ofclaim 1, wherein R1 and R2 are independently selected from: —CF₂CF₂—,—CF₂CF₂OCF₂CF₂—, —CF₂CF(CF₃)—O—CF₂CF₂—.
 15. The method of claim 1further comprising providing an initiator in step (a), wherein theinitiator is a perfluorinated peroxide.
 16. The method of claim 15wherein the perfluorinated peroxide is selected fromCF₃OC₂F₄COOOCOC₂F₄OCF₃ and C₃F₇COOOCOC₃F₇.
 17. The method of claim 1wherein the highly fluorinated oligomeric sulfonyl halide is aperfluorovinyl sulfonyl halide.
 18. The method of any of claim 17wherein the perfluorovinyl sulfonyl halide is selected from:

and combinations thereof.
 19. The method of claim 1 wherein reducing isconducted using sodium borohydride, potassium borohydride, lithiumaluminum hydride, NH₂NH₂, K₂SO₃, Na₂SO₃, NaHSO₃ or KHSO₃ as a reducingagent.